<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>内容过滤器</title>
        <script src="./jquery-3.6.0.min.js" type="text/javascript"></script>
    <script>
$(document).ready(function(){
    $("td:empty").css("background","gery")
})
    </script>
</head>
<body>
<table id="employees" width="200" border="1">
    <tr>
    <th>id</th>
    <th>姓名</th>
    <th>性别</th>
    <th>年龄</th>
    <th>学历</th>
</tr>
<tr>
    <td>001</td>
    <td>张三</td>
    <td>女</td>
    <td></td>
    <td>大专</td>
</tr>
<tr>
    <td>002</td>
    <td>李四</td>
    <td>男</td>
    <td></td>
    <td>大专</td>
</tr>
<tr>
    <td>003</td>
    <td>张三</td>
    <td>女</td>
    <td></td>
    <td>本科</td>
</tr>
</table>
</body>
</html>